The conventional form of a shovel includes an elongated shaft having a hand grip portion at one end and a shovel blade at the opposite end. In order to utilize a conventional shovel, an individual grasps an intermediate portion of the shaft with one hand and the hand grip portion of the shovel with the other hand. This forces the individual to bend over and twist their torso at an uncomfortable position while gathering snow, dirt, debris, etc., onto the face of the blade. The individual then lifts the shovel at the hand grip on the intermediate portion of the shaft using the opposite hand grip near the end of the shaft as a pivot. Along with lifting the shovel in this manner, the individual uses their back muscles to pull the shoveled material upward, adjusting their body into a standing position; this creates the potential for serious back injury. The individual may then carry the shoveled material in an upright position or toss the shoveled material by using the hand grip near the end of the shaft as the pivot, the hand grip in the intermediate portion of the shaft as the throwing arm, and twisting their upper body at the waist to gain tossing or launching momentum. This method additionally results in an ergometrically inefficient and potential injury causing working position.
The present invention relates to a shovel such as that used to clear snow from a driveway or walkway. More particularly, this invention is directed to a manual shovel apparatus having two handles urged together by an elastomeric element, whereby a coaxial pivot of the handles is positioned over the centroid of force upon the shovel blade while in use. The user grasps a handle in each hand holding the handles on the outside of their waist. The user then pushes the shovel with both handles in a snowplow manner. The coaxial pivot allows the user to angle the face of the blade for pushing the shoveled material in an angled direction, as one handle is affixed to the blade and the other handle is pivotally attached to the blade. Therefore, the action integrated into the shovel is a forward-plowing action, rather than the conventional scooping-lifting-throwing action.
In looking at the prior art in this area several patents teach clearing snow from a driveway or walkway using two or more handles whereby the handles are stationary, starting with U.S. Pat. No. 7,077,444 to Kaufman et al. disclosed is a two handled shovel for clearing a surface of snow, dirt, gravel, or other debris. The shovel in Kaufman comprises a blade having a leading edge which contacts the surface, a main handle attached to the blade and an auxiliary handle pivotally attached to the blade near the leading edge. To use the Kaufman shovel, the user holds the main and auxiliary handles and pushes the shovel forward to scoop up the snow or debris. However, to dump the snow or debris collected in the blade of the Kaufman shovel, the user must pivot the blade on a point at either end of the leading edge by manipulating the main and auxiliary handles. This requires lifting and twisting and puts strain on the user's back. Moreover, because Kaufman's shovel employs the two handles in a vertical plane with one above the other, the user could be speared by either or both handles if the blade were to catch on an uneven surface or crack on a sidewalk for instance. (Column 1, lines 53-63).
Continuing in U.S. Pat. No. 4,103,954 to Vaslas disclosed is a snow shovel having a conventional main handle and a novel auxiliary handle which enable the shovel to be easily manipulated by the user without having to bend over or unduly strain the users back in the shoveling operation. The auxiliary handle of Vaslas' shovel includes a rigid cross-brace bar which is connected at one end to the auxiliary handle rods and has means at its other end for adjustably coupling it and releasably locking it to the main handle rod in a variety of different adjustment positions. While the shovel in Vaslas does lessen the strain on the user's back, the user still must twist his back to operate the shovel. Also, the single handle of Vaslas' shovel could spear the user. (Column 1, lines 58-64. Column 2, lines 26-32). Next, in U.S. Pat. No. 5,048,883 to Waluk disclosed is a snow shovel/scraper having a dual handle arrangement, where the upper ends of the handles curve at a right angle to fit into the underarm area of the user, and a crossbar mounted along the length of the rails and are turned downwardly from the rails for grasping by the hands of the user. This arrangement allows Waluk's shovel to be pushed using the shoulders and hands of the user in a vigorous pushing action. However, should Waluk's shovel catch on a crack or uneven surface, the shovel would be forced back into the user's shoulders, which could potentially cause the user to be injured. (Abstract).
Yet further, in the pivotal shovel arts, a shovel such as in U.S. Patent Application Publication Number 2007/0108783 to Petruzelli having a laterally adjustable snow shovel, U.S. Pat. No. 6,883,845 to Douziech having a pivotable second handle, and U.S. Pat. No. 3,938,843 to Pahl having pivotable fulcrum with the handle being placed under the user's arm pit acting as a lever are discussed. Starting with U.S. Patent Application Publication Number 2007/0108783 to Petruzelli disclosed is a laterally adjustable snow shovel reinforced by braces for preventing the blade from turning or wobbling when snow is shoveled. The shovel in Petruzelli includes a handle assembly being pivotally connected to a blade for pivoting between a first position at a first acute angle between the horizontal blade axis and the vertical handle axis and a second position at a second acute angle between the horizontal blade axis and the vertical handle axis. The blade of Petruzelli's shovel also has a third position at a right angle between the vertical handle axis and the horizontal blade axis. The shovel in Petruzelli includes a pivoting means for pivoting the handle assembly with respect to the blade. The pivoting means of Petruzelli's shovel includes either a bracket that pivots with respect to the blade or a bracket that is permanently attached to the blade but is also pivotally connected to the lower handle assembly. The shovel in Petruzelli does require that the user stoop at an awkward angle and twist in operating the shovel. Additionally, the single handle is capable of spearing the user. (Page 1, paragraph 10 and 12-13). Continuing, in U.S. Pat. No. 6,883,845 to Douziech discloses a two-handled snow shovel having rotatable hand grips at each handle. The shovel in Douziech comprises a shaft with a D-shaped handle with a rotating grip located at the upper end of the shaft. The grip of Douziech's shovel rotates about a rod that extends between the sides of the handle. In Douziech, the lower end of the shaft is inserted into a shaft insert sleeve attached to the rear side of the blade. Mounted near the top of the blade of Douziech's shovel on the rear side is a second handle assembly capable of pivoting forwards and backwards. While Douziech's shovel is two handled, it is still capable of spearing the user. (Column 1, lines 41-49), being much the same as Vaslas as previously described.
Looking toward U.S. Pat. No. 3,938,843 to Pahl disclosed is a manually operated snow mover comprising a curved wooden scoop, a pair of space handle arms fastened to the convex back of the scoop, a lower cutting edge and a leading circular cutting toe on the scoop, the free ends of the arms being spaced apart so the longer flat arm may be placed under a user's arm pit to act as a lever. With the other arm in Pahl having a long handle portion to form one half of a fulcrum and a cross arm with a handle portion connected across the two arms and extending over a considerable distance to be grasped by a user's hand to form the other half of the fulcrum whereby the fulcrum has a circular motion acting as a movable imaginary pivot, the center of this pivot floating up and down and side to side as the snow mover is used in a sweeping motion. The snow mover in Pahl does require the user to pull on the handles, which requires greater effort than pushing. (Column 2, claim 1).
Also, similarly looking at U.S. Pat. No. 5,440,828 to Simpson having a slidable handle within the channel over a range of angular positions, (Abstract), U.S. Pat. No. 2,463,150 to Camp having a handle held in an adjusted position by means of a clamping lever pivotally mounted upon the rear side of the blade, (Column 1, lines 25-28), U.S. Pat. No. 813,983 to Luney having a snow shovel with a pivoted blade which turns laterally to a limited extent, so that the snow may be carried up and off the blade at one side thereof and be deflected in case the blade strikes an obstruction, (Column 1, lines 13-18), and U.S. Pat. No. 5,829,808 to Colla having a single handled shovel which allows infinite adjustment side to side of the handle. **If the user of Colla's shovel wants to move snow to either the left or right side, he/she can loosen the fasteners for securing the handle in its various positions, and move the handle either to the left or the right and tighten the fasteners, which hold the handle in the new position. (Column 1, lines 30-32. Column 2, lines 13-14 and 29-34).
The prior art patents teaching of shoveling using one or more handles whereby one or more handles are stationary allowing the user to lift the shoveled material in the same tralatitious manner, whereby the user is still resorting to employing their back in a twisted orientation to shovel the snow, dirt, debris, etc. as in such patents: U.S. Pat. No. 4,944,541 to Waldschmidt, U.S. Pat. No. 6,830,271 to Piscopo et al., and U.S. Pat. No. 5,054,830 to Nisenbaum.
The prior art patents utilizing a single pivotable handled shovel allow the user to shovel in a plurality of angular positions by different means. The shovel requires the user to angle the shovel by manually detaching and reattaching the handle as seen in U.S. Pat. No. 4,538,847 to Lapshansky, by fastening means as seen in U.S. Pat. No. 2,463,150 to Camp and U.S. Pat. No. 5,829,808 to Colla, by tightening means as seen in U.S. Pat. No. 813,983 to Luney, or by bracketing or in an alternate construction, frame pivot support as seen in U.S. Pat. No. 5,440,828 to Simpson.
However, the cited prior art shovels do not teach a shovel having two or more handles urged together by an elastomeric element, whereby the coaxial pivot of the handles is positioned adjacent to the centroid of force upon the shovel. The coaxial pivot allows the user to interchange handles by passing the handles freely from one hand to the other permitting the user to change angles, without the need for detaching and reattaching, fastening, tightening, bracketing, or otherwise having to manually adjust the frame support.
Additionally, none of the aforementioned cited prior art shovels allow the user to grasp a handle in each hand, holding the handles on the outside of their waist or more particularly their torso, whereby the user pushes the shovel with both handles in a snowplow type manner. This process eliminates the conventional scooping-lifting-throwing method attributed to back injuries and also works in an ergonometrically efficient shoveling process. Accordingly, it can be appreciated that there is a continuing need for and interest in improvements to shovels, and in this respect, the present invention addresses this need and interest.